Run annotated methods on the Main Thread. The Fody plugin you never realized you needed.

Install via NuGet using:

PM> Install-Package RunOnMainThread.Fody

Then add it to your FodyWeavers.xml:

<?xml version="1.0" encoding="UTF-8" ?>
<Weavers>
  <RunOnMainThread />
</Weavers>

The package will add a static MainThreadDispatcher class with a void RunOnMainThread(Action action) method. You can use it directly to access the main thread from anywhere in your app:

private void ShowDialogUsingDispatcher()
{
    MainThreadDispatcher.RunOnMainThread(() =>
    {
        Console.WriteLine("Main thread!");
    });
}

The cool part about this library, though, is that you can instead annotate your method with the RunOnMainThreadAttribute and all that boilerplate will be added for you. The method below is the same as the one in the static class example:

[RunOnMainThread]
private void ShowDialogUsingWeaver()
{
    Console.WriteLine("Main thread!");
}

For more examples, check out the sample apps.